5-(hexyloxy)-2,2-dimethyltetrahydrofuran

Toxicity to aquatic algae and cyanobacteria

Description of key information

A study was performed to assess the effect of the test material on the growth of the green alga Pseudokirchneriella subcapitata.The method followed that described in the OECD TG No 201. Following a preliminary range-finding test, the algae were exposed to WSF solutions of the test material at loading rates of 1.0, 3.2, 10, 32 and 100 mg/L (three replicate flasks per concentration) for 72 hours, under constant illumination and shaking at a temperature of 21 - 23 °C.
Samples were taken from all treatments at t = 0 , 24 and 72h and analysed with a validated GC-FID method. The range tested based on TWA (Time Weighted Average) concentrations corresponded with 0.33, 0.85, 3.1, 11 and 32 mg/L. The measured concentrations were comparable between the replicates with and without algae in the test group representing 10% WSF, indicating that the decrease of test substance in the test solution during the test period was not caused by adsorption to algae. 
Statistically significant inhibition of growth rate was found at measured concentrations of 0.85 mg/L and higher, however, the effect observed at 0.85 and 3.1 mg/L was considered biologically insignificant (<10%) and therefore the NOEC based on TWA concentrations was set to 3.1 mg/L.
The ErC10 and ErC50 based on TWA concentrations were 10 and 14 mg/L, respectively.

Key value for chemical safety assessment

EC50 for freshwater algae:

14 mg/L

EC10 or NOEC for freshwater algae:

10 mg/L